a(n) = 1 + product of first n positive triangular numbers (A000217).

A061213

a(n) = 1 + product of first n positive triangular numbers (A000217).

Terms

    a(0) =2a(1) =4a(2) =19a(3) =181a(4) =2701a(5) =56701a(6) =1587601a(7) =57153601a(8) =2571912001a(9) =141455160001

External references